Destination route guiding method

ABSTRACT

A destination navigation method is disclosed, which includes locating present position and destination, searching route to the destination. The method includes giving driving guidance along a route set on basis of a predetermined evaluation index or selection of driver and further determining whether searched route contains a short distance lane change section, where a road having many lanes and distance between an entryway to the road having many lanes and a junction (exit way) is short in order to give notice that it is coming and for driver to avoid it if necessary because the short distance lane change section may cause stress and fatigue especially for an unskilled driver.

This application is the national phase under 35 U.S.C. §371 of PCTInternational Application No. PCT/JP01/00581 which has an Internationalfiling date of Jan. 29, 2001, which designated the United States ofAmerica.

TECHNICAL FIELD

The present invention relates to a destination navigation method usedfor an in-vehicle navigation system for giving a driving guidance alonga route to a set designation (hereinafter referred to as a routing lineto destination) and, in particular, to a destination navigation methodin a case when the routing line to destination has a section requiring alane change.

BACKGROUND ART

FIG. 1 is an illustration to show a destination navigation method in theprior art, for example, disclosed in Japanese Patent Laid OpenPublication No. 2000-18956. As shown in FIG. 1, when a routing line todestination for connecting the present position to a destination is setin a navigation system, every time a vehicle comes near to a branchpoint (hereinafter referred to as a guide branch point) where a guidanceis given to a driver along the routing line to destination, a drivingguidance relating to the guide branch point is given, for example, bymeans of voice. In this case, for example, a distance to the guidebranch point and a direction to turn such as “xxx meter ahead, Turn tothe right” are announced by voice. Further, as shown in FIG. 1, not onlythe distance to the guide branch point but also the position of lane topass such as “xxx meter ahead, To xxxx, Go to right end lane” isannounced by voice.

Since the destination navigation method used in the navigation system inthe prior art gives the driver the driving guidance in the mannerdescribed above, even in the case when the routing line to destinationhas a section requiring a lane change, it gives the driver only aguidance of the lane to pass at an every predetermined appropriatetiming when the vehicle comes near to the guide branch point. However,in a case when there is a road having many lanes on the routing line todestination and the vehicle is driven along the routing line todestination, if a distance for an entryway or a junction (exit way) isshort to/from a highway having many lanes along the routing line todestination, it is necessary to make a large lane change in a shortdistance but, even in this case, as described above, the destinationnavigation method in the prior art does not give a special alarm butonly gives an appropriate guidance of a lane change. Therefore, thedestination navigation method in the prior art requires the driver tomake a large lane change in a short time without informing the driver ofthe necessary large lane change, in advance, which presents a problem ofraising the possibility that the driver, in particular, an unskilleddriver who gets a driving license a short time ago, is given a mentalfatigue and is uselessly tired in driving.

Further, when the driver searches a route from the present position ofthe vehicle to the destination, the destination navigation method in theprior art uses a travel distance, a driving time, expenses including ahighway toll (hereinafter referred to as a cruising toll) as evaluationindexes for selecting the routing line to destination, but does not takeinto account whether or not the routing line to destination includes asection requiring the driver to make a large lane change in a shortdistance (hereinafter referred to as a short-distance lane changesection) in performing a search for the routing line to destination.Therefore, the destination navigation method in the prior art presents aproblem that it can not respond to the request of the driver who desiresto avoid such a short-distance lane change section.

The present invention has been made to solve the problem describedabove, and it is an object of the present invention to provide adestination navigation method for informing or warning a driver that thevehicle is coming near to the short-distance lane change section at thetime when a vehicle comes near to a short-distance lane change section.

Further, it is another object of the present invention to provide adestination navigation method for judging whether or not a set routingline to destination includes a short-distance lane change section andfor changing the set routing line to destination to a bypath includingno short-distance lane change section according to the selection of adriver.

DISCLOSURE OF THE INVENTION

A destination navigation method in accordance with the present inventionincludes a step of judging whether or not one searched route or aplurality of searched routes include a short-distance lane changesection.

This makes it possible to set a routing line to destination on the basisof the presence or absence of the short-distance lane change section,and thus can produce an effect of responding to the request of a driverto desire to bypass the short-distance lane change section.

The destination navigation method in accordance with the presentinvention further includes a step of making the driver select whether ornot the driver avoids passing the short-distance lane change section.

This make it possible to reflect a driver's intention of avoiding oraccepting passing the short-distance lane change section to the settingof the routing line to destination, and thus can produce an effect ofsetting the routing line to destination in accordance with the driver'sintention.

The destination navigation method in accordance with the presentinvention further includes a step of judging whether or not one route ora plurality of routes among the routes for connecting the presentposition to the destination include the short-distance lane changesection and a step of making the driver select whether or not the driveravoids passing the short-distance lane change section only in the casewhen the route is judged as including the short-distance lane changesection.

This makes it possible urging the driver to select the route only in thecase when the route having a possibility of being set as the routingline to destination includes the short-distance lane change section andthus can produce an effect of eliminating the need for asking anunnecessary selection of the driver and of improving the convenience ofa navigation system.

The destination navigation method in accordance with the presentinvention further includes a step of judging whether or not one route orthe plurality of routes for connecting the present position to thedestination have an appropriate route including no short-distance lanechange section.

Thereby, in the case when the driver desires to avoid passing theshort-distance lane change section, if an appropriate route including noshort-distance lane change section is found, it is possible toautomatically set the route as the routing line to destination, and thusto produce an effect of setting the routing line to destination that thedriver desires without asking an unnecessary selection of the driver.

The destination navigation method in accordance with the presentinvention further includes a step of informing the driver that there isthe short-distance lane change section on the routing line todestination in a case when the set routing line to destination includesthe short-distance lane change section, by an use of image informationor voice information.

Thereby, it make possible for the driver to recognize in advance thatthe driver passes a route including the short-distance lane changesection and thus to produce an effect of making the driver preparedriving for passing the short-distance lane change section and ofreducing the mental fatigue of the driver.

The destination navigation method in accordance with the presentinvention further includes a step by which the driver is given an alarmor a driving guidance relating to the short-distance lane change sectionevery time the driver comes near to the short-distance lane changesection in the case when the set routing line to destination includesthe short-distance lane change section.

Thereby, it makes possible to call a driver's attention before thedriver passes the short-distance lane change section and thus to producean effect of improving safety in driving a vehicle.

The destination navigation method in accordance with the presentinvention further includes a step of displaying one route or a pluralityof routes including a short-distance lane change section and one routeor a plurality of routes including no short-distance lane change sectionin such a manner that they can be discriminated from each other, and astep of making the driver select one route out of the plurality ofroutes displayed in the said displaying step.

Thereby, even in the case when the route including no short-distancelane change section is judged as being not appropriate, the route can beset as the routing line to destination by the selection of the driver,and it is possible to produce an effect of expanding the alternatives ofcruising routes and improving the effectiveness of the navigationsystem.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration to show a destination navigation method in theprior art.

FIG. 2 is a block diagram of a navigation system using a destinationnavigation method in accordance with an embodiment 1 of the presentinvention.

FIG. 3 is a flow chart to show a destination navigation method inaccordance with the embodiment 1 of the present invention.

FIG. 4 is a flow chart to show a destination navigation method inaccordance with an embodiment 2 of the present invention.

FIG. 5 is a flow chart to show a destination navigation method inaccordance with an embodiment 3 of the present invention.

FIG. 6 is a flow chart to show a modification of the destinationnavigation method in accordance with the embodiment 3 of the presentinvention.

BEST MODE FOR CARRYING OUT THE INVENTION

In order to be understood the present invention in more detail, the bestmodes for carrying out the present invention will be hereinafterdescribed with reference to accompanying drawings.

Embodiment 1

FIG. 2 is a block diagram of a navigation system using a destinationnavigation method in accordance with the embodiment 1 of the presentinvention. In FIG. 2, a reference numeral 1 denotes a position detectorfor determining the present position of a vehicle; 2 denotes a map datainput device constituted usually by a CD-ROM or a DVD as a storagemedium; 3 denotes a group of operating switches; 4 denotes acommunications device for performing communications with an externalinformation center to get traffic information and the like; 5 denotes adisplay device for displaying a map, a menu relating to variousoperations and the like; 6 denotes a speaker; 7 denotes a navigationelectronic control unit (Hereinafter referred to as “navigation ECU”)connected to the position detector 1, the map data input device 2, thegroup of operating switches 3, the communications device 4, the displaydevice 5 and the speaker 6 to perform various kinds of controls relatingto a navigation system; and 8 denotes an external memory connected tothe ECU 7. In this respect, the position detector 1 is constituted by agyroscope, a speed sensor for detecting the speed of a vehicle, and aGPS receiver for a GPS for detecting the position of the vehicle on thebasis of electric waves from a satellite and the like.

FIG. 3 is a flow chart to show a destination navigation method inaccordance with the embodiment 1 of the present invention. After thepower is turned on, at the timing when a map or a menu is displayed onthe display device 5 by the navigation ECU 7 or when an instruction isgiven by voice from the speaker 6, a driver inputs a destination byoperating the group of operating switches 3. Further, the navigation ECU7 determines the present position of the vehicle on the basis of thedata from the satellite which is obtained by a GPS receiver in theposition detector 1. Thereby, the navigation ECU 7 locates the presentposition of the vehicle and the destination (step ST1). Next, thenavigation ECU 7 inquires of the driver whether or not the driver avoidspassing a short-distance lane change section by the menu displayed onthe display device 5 or the like and urges the driver to select arouting line to destination (step ST2). In this respect, a criterion forjudging whether or not a routing line to destination includes ashort-distance lane change section, a method for setting the criterion,and a specific example of the short-distance lane change section will bedescribed later. In the case when the driver selects to accept passingthe short-distance lane change section by operating the group ofoperating switches 3 in response to the inquiry in the step ST2, thatis, in the case when “No” is selected in the step ST2, the navigationECU 7 performs an ordinary route search without taking into account theshort-distance lane change section and selects the most appropriateroute on the basis of a predetermined evaluation index or the selectionof the driver and sets the route as a routing line to destination (stepST3). Herein, there may be some cases that a route including theshort-distance lane change section is set as the routing line todestination, and there may be other cases that a route not including theshort-distance lane change section is set as the routing line todestination. Further, in the case when the driver selects to avoidpassing the short-distance lane change section, that is, “Yes” isselected in the step ST2, the navigation ECU 7 checks a presence orabsence of the short-distance lane change section in performing therespective route searches and keeps a result of the presence or absenceof the short-distance lane change section as attribute data for therespective searched routes (step ST4).

Next, the navigation ECU 7 judges whether or not there is an appropriateroute including no short-distance lane change section (step ST5).Herein, a criterion for judging whether or not there is an appropriateroute including no short-distance lane change section will be describedlater. Further, in the case when it is judged that there is anappropriate route/or are appropriate routes including no short-distancelane change section, that is, the result of judgment is “Yes” in thestep ST5, the navigation ECU 7 selects the most appropriate route amongthe result on the basis of the predetermined evaluation index or theselection of the driver and sets the route as the routing line todestination (step ST6). Further, in the case when it is judged thatthere is no an appropriate route including no short-distance lanechange, that is, the result of judgment is “No” in the step ST5, thenavigation ECU 7 selects the most appropriate route among one route or aplurality of routes including the short-distance lane change section,determined in the step ST4, on the basis of the predetermined evaluationindex or the selection of the driver and sets the route as the routingline to destination (step ST7). In the case when it is judged that thereis no an appropriate route including no short-distance lane changesection in the step ST5 and when the route including the short-distancelane change section is set as the routing line to destination in thestep ST7, and in the case when it is selected to accept passing theshort-distance lane change section in the step ST2 and when the routeincluding the short-distance lane change section is set as the routingline to destination in the step ST3, the navigation ECU 7 informs thedriver that there is the short-distance lane change section on therouting line to destination by means of image information such as acharacter and a figure displayed on the display device 5 or voiceinformation output from the speaker 6 (step ST8). Then, the navigationECU 7 gives the driver a driving guidance to the destination along therouting line to destination set in any one step of the step ST3, thestep ST6 and the step ST7 (step ST9).

Next, the section requiring a large lane change in a short distance,that is, the short-distance lane change section will be described.First, the conditions of the route in which there is the short-distancelane change section on the routing line to destination will be describedas examples. The conditions of the route include, firstly, a case when adistance for an entryway or a junction (exit way) is short to/from ahighway having many lanes along the routing line to destination,secondly, a case when a distance between intersections is short on aroad having many lanes, thirdly, a case when a distance between anintersection and the next U-turn point is short on a road having manylanes, and, fourthly, a case when a distance between an intersection andan entrance to a parking lot is short on a road having many lanes.

Further, in order to judge whether or not an arbitrary section on thesearched route includes the short-distance lane change section, it isnecessary to quantitatively define the short-distance lane changesection. There are various methods for quantitatively defining theshort-distance lane change section and one of them is, for example, touniformly define the short-distance lane change section without takinginto account the conditions of the road, such as “a section requiringchanging four or more lanes in 100 meters irrespective of the kind ofroad”, or “a section requiring changing five or more lanes in 50 metersfor an ordinary road and three or more lanes in 200 meters for ahighway”. Further, a method is also thought in which a section isdefined on the basis of the degree of difficulty of the lane changecalculated on the basis of the equation expressed by the followingequation (1).

Degree of difficulty

=A×number of lanes to be changed×speed limit/ section distance  (1)

In the above equation (1), A is a coefficient set at an appropriatevalue to limit the degree of difficulty in an appropriate range. Thedegree of difficulty calculated by the equation (1) is compared with apredetermined threshold value and in the case when the degree ofdifficulty is larger than the predetermined threshold, it is judged thatthe section is the short-distance lane change section and in the casewhen the degree of difficulty is smaller than the predeterminedthreshold, it is judged that the section is not a short-distance lanechange section. Here, the definition relating to the short-distance lanechange section is not limited to the definition described above but adifferent definition may be used according to information relating tothe road received by the communications device 4. Further, it is alsorecommendable that several alternatives are prepared for the definitionrelating to the short-distance lane change section and the definitionsselected by the driver may be used.

Next, the evaluation index will be described which is used for selectingthe most appropriate route among a plurality of routes in the step ST3,the step ST6 or the step ST7. In the case when it is not necessary totake into account whether or not the routing line to destinationincludes the short-distance lane change section, as in the step ST3 andthe step ST6, a travel distance, a driving time, and a cruising toll areused as the evaluation indexes as is a usual case. In contrast, in thecase when the most appropriate route is selected among the routesincluding the short-distance lane change section, as in the step ST7, itis thought that not only the above described evaluation indexes but alsothe degree of difficulty of the lane change calculated, for example, bythe equation (1) relating to the short-distance lane change section isused as the evaluation index.

Next, performing a search for the appropriate route including noshort-distance lane change section in the step ST5 will be described. Inthe step ST5, if there is a route for connecting the present position ofthe vehicle to the destination and including no short-distance lanechange section, there are two following cases for the route: a case whenthe route is more advantageous than or equal to a route including theshort-distance lane change section in the travel distance, the drivingtime, and the cruising toll; and a case when the route is moredisadvantageous in the travel distance, the driving time, and the tollthan the route including the short-distance lane change section. In theformer case, it can be said that there is an appropriate route includingno short-distance lane change section, but in the latter case, if thedegree of disadvantage is very large, the route can not be adopted as anappropriate route, so that it is necessary to set a criterion forjudging a route is an appropriate route or not. It is recommendable toset a criterion such that one value or a plurality of values amongdifferences in the travel distance, the driving time and the cruisingtoll between the route to be judged and the route including theshort-distance lane change section are compared with a predeterminedthreshold thereof and that if the value is smaller than the threshold,the route to be judged is determined as being an appropriate route, andthat if the value is larger than the threshold, the route to be judgedis determined as being not an appropriate route. For example, it isrecommendable to set a criterion such that if the difference in thetravel distance between the route to be judged and the route includingthe short-distance lane change section is less than 5 km, the route tobe judged is determined as being an appropriate route. In this regard,for the setting of this criterion, it is also recommendable that thecriterion stored beforehand in the ROM of the navigation system areuniformly used or that one of several alternatives prepared for thecriterion are selected and set as the criterion by the driver.

Further, while the driving guidance to the destination along the routingline to destination is being given to the driver in the step ST9, in thecase when the set routing line to destination includes theshort-distance lane change section, it is preferable to give the driverby the navigation ECU 7 a driving guidance or an alarm relating to theshort-distance lane change section in every time interval the vehiclecomes near to the short-distance lane change section. With regard to thedriving guidance or the alarm it is possible for the driver to inform ofthe driving guidance or the alarm by means of voice information from thespeaker 6 or image information such as characters or figures displayedon the display device 5.

As described above, according to the embodiment 1, in the destinationnavigation method including the step ST1 of locating the presentposition and the destination, the step ST3 of searching routes forconnecting the present position to the destination, and the step ST9 ofgiving the driving guidance to the destination along the routing line todestination set on the basis of the predetermined evaluation index orthe selection of the driver, the improvement includes the step ofjudging whether or not one searched route or the plurality of searchedroutes include the short-distance lane change section and thus can setthe routing line to destination on the basis of the presence or absenceof the short-distance lane change section, so that it is possible toproduce an effect of responding to the request of the driver who desiresto bypass the short-distance lane change section.

Further, since the destination navigation method includes the step ST2of making the driver select whether or not the driver avoids passing theshort-distance lane change section, it is possible to reflect thedriver's intention of avoiding or accepting passing the short-distancelane change section on the setting of the routing line to destinationand to produce an effect of setting the routing line to destination inaccordance with the driver's intention.

Further, the destination navigation method includes the step ST5 ofjudging whether or not one route or the plurality of routes forconnecting the present position to the destination have an appropriateroute including no short-distance lane change section. Thus, in the casewhen the driver desires to avoid passing the short-distance lane changesection, if the driver finds an appropriate route including noshort-distance lane change section, the driver can automatically set theroute as the routing line to destination, so that it is possible toproduce an effect of setting the routing line to destination that thedriver desires without requiring an unnecessary selection of the driver.

Still further, the destination navigation method includes the step ST8of informing the driver that there is the short-distance lane changesection on the routing line to destination by means of the imageinformation or the voice information in the case when the set routingline to destination includes the short-distance lane change section.Thus, the driver can recognize in advance that the driver will pass theroute including the short-distance lane change section, so that it ispossible to make a driver prepare for passing the route including theshort-distance lane change section and to produce an effect of reducingthe mental fatigue of the driver.

Still further, in the case when there is the short-distance lane changesection on the routing line to destination, the destination navigationmethod gives the driver the alarm or the driving guidance relating tothe short-distance lane change section in the step ST9 every timeinterval the vehicle comes near to the short-distance lane changesection. Thus, it is possible to call the driver's attention before thedriver passes the short-distance lane change section and to produce aneffect of improving safety relating to the driving of the vehicle.

Embodiment 2

FIG. 4 is a flow chart to show a destination navigation method inaccordance with an embodiment 2 of the present invention. In FIG. 4, thesame reference numerals as in FIG. 3 denote the same or equivalentprocesses and the further description thereof will be omitted. In thisembodiment 2, in the case when it is judged that there is no anappropriate route including no short-distance lane change route, thatis, the result of judgment is “No” in the step ST5, the navigation ECU 7displays one route or a plurality of routes including the short-distancelane change section, which is determined in the step ST4, and one routeor a plurality of routes including no short-distance lane changesection, which is judged to be not appropriate, on the display device 5,for example, by means of different colors in such a way that the routescan be discriminated from each other (step ST11). Next, the navigationECU 7 makes the driver select one route out of the plurality of routesdisplayed on the display 5 (step ST12). If the route including noshort-distance lane change section is selected, that is, “Yes” isselected in the step ST12, the selected route is set as the routing lineto destination (step ST6). Or, if the route including the short-distancelane change section is selected, that is, “No” is selected in the stepST12, the selected route is set as the routing line to destination (stepST7). Here, with regard to the selection at ST12, it is alsorecommendable to make the driver select the kind of route, that is, theroute including the short-distance lane change section or the routeincluding no short-distance lane change section. In this case, if “Yes”is selected in the step ST12, the most appropriate route is selectedamong one route or the plurality of routes including no short-distancelane change section on the basis of the predetermined evaluation indexand is set as the routing line to destination. Further, if “No” isselected in the step ST12, the most appropriate route is selected amongone route or the plurality of routes including the short-distance lanechange section on the basis of the predetermined evaluation index and isset as the routing line to destination.

As described above, this embodiment 2 can produce the same effect as theembodiment 1, and in addition to the processes of the embodiment 1, inthe case when the result of judgment in the step 5 is “No”, theembodiment 2 includes the step ST11 of displaying one route or theplurality of routes including the short-distance lane change section andone route or the plurality of routes including no short-distance lanechange section in such a way that they can be discriminated from eachother and the step ST12 of making the driver select one route out of theplurality of routes displayed in the step ST11. Thus, even in a casewhen it is judged the route including no short-distance lane changesection is not appropriate, it is possible to set again the route as therouting line to destination by the selection of the driver and thus toproduce an effect of expanding the alternatives of the driving routesand improving the convenience of the navigation system.

Embodiment 3

FIG. 5 is a flow chart to show a destination navigation method inaccordance with an embodiment 3 of the present invention. The presentembodiment 3 is different from the embodiment 1 in that only in a casewhen one route or a plurality of routes for connecting the presentposition to the destination include a short-distance lane changesection, the driver is made to select whether or not the driver avoidspassing the short-distance lane change section. In FIG. 5, the samereference numerals as in FIG. 3 denote the same or equivalent processesand the further description thereof will be omitted. In the step ST1,the navigation ECU 7 locates the present position of the vehicle and thedestination and then performs a search for a route for connecting thepresent position to the destination (step ST21). Next, the navigationECU 7 judges whether or not one route or a plurality of routes to be setas a routing line to destination among the routes for connecting thepresent position to the destination include a short-distance lane changesection (step ST22). In the case when the route is judged as includingno short-distance lane change section, that is, the result of judgmentis “No” in the step ST22, the navigation ECU 7 selects the mostappropriate route on the basis of the predetermined evaluation index orthe selection of the driver and sets the route as the routing line todestination (step ST23). Further, in the case when the route is judgedas including the short-distance lane change section, that is, the resultof judgment is “Yes” in the step ST22, the navigation ECU 7 inquires ofthe driver whether or not the driver avoids passing the short-distancelane change section by means of the menu or the like displayed on thedisplay device 5 to urge the driver to select the route (step ST2).

As described above, this embodiment 3 can produce the same effect as theembodiment 1, and in addition to the processes of the embodiment 1, theembodiment 3 includes the step ST21 of performing a search for a routefor connecting the present position to the destination after the presentposition and the destination are located, the step ST22 of judgingwhether or not one route or a plurality of routes for connecting thepresent position to the destination include a short-distance lane changesection, and the step ST2 of making the driver select whether or not thedriver avoids passing the short-distance lane change section only in thecase when the route is judged as including the short-distance lanechange section. In this manner, only in the case when the route having apossibility of being set as the routing line to destination includes theshort-distance lane change section, the driver is urged to select theroute, so that it is possible to produce an effect of eliminating theneed for asking an unnecessary selection of the driver and thus toimprove the convenience of the navigation system.

Further, FIG. 6 is a flow chart to show a modification of thedestination navigation method in accordance with the embodiment 3 of thepresent invention. The same as in the case of the embodiment 2, in themodification, to the embodiment 3 are added a step ST11 of displayingone route or a plurality of routes including the short-distance lanechange section and one route or a plurality of routes including noshort-distance lane change section, which are judged as being notappropriate, in such a manner that they can be discriminated from eachother, and a step ST12 of making the driver select one among theplurality of displayed routes. In this case, the modification of theembodiment 3 can produce the same effect as the embodiment 2, and sincethe driver is made to select whether or not the driver avoids passingthe short-distance lane change section only in the case when the routeis judged as including the short-distance lane change section, only inthe case when the route having a possibility of being set as the routingline to destination includes the short-distance lane change section, thedriver is urged to select the route. Therefore, it is possible toproduce an effect of eliminating the need for asking an unnecessaryselection of the driver and thus to improve the convenience of thenavigation system.

Incidentally, it is not intended to limit the present invention to thedestination navigation methods described in the embodiment 1 to theembodiment 3, but the present invention can be put into practice invarious alternatives, modifications and equivalents included within thesprit and scope of the invention defined by the appended claims.

Industrial Applicability

As described above, the destination navigation method in accordance withthe present invention is appropriate for guiding a route bypassing asection requiring a large lane change in a short distance in anavigation system.

What is claimed is:
 1. A destination navigation method comprising thesteps of: locating a present position and a destination; searchingroutes for connecting the present position to the destination; giving adriving guidance to the destination along a routing line to thedestination set on the basis of a predetermined evaluation index or aselection of a driver; and judging whether or not at least one searchedroute includes a short-distance lane change section by quantitativelydefining said short-distance lane change section according to a lengthof said section.
 2. The destination navigation method as claimed inclaim 1, characterized by further comprising a step of making the driverselect whether or not the driver avoids passing the short-distance lanechange section.
 3. The destination navigation method as claimed in claim2, characterized by further comprising a step of judging whether or notthe at least one route among the routes for connecting the presentposition to the destination includes the short-distance lane changesection and a step of making the driver select whether or not the driveravoids passing the short-distance lane change section only in a casewhen the route is judged as including the short-distance lane changesection.
 4. The destination navigation method as claimed in claim 1,characterized by further comprising a step of judging whether or not atleast one route for connecting the present position to the destinationhas an appropriate route including no short-distance lane changesection.
 5. The destination navigation method as claimed in claim 1,characterized by further comprising a step of informing the driver thatthere is the short-distance lane change section on the routing line todestination in a case when the set routing line to destination includesthe short-distance lane change section, by an use of image informationor voice information.
 6. The destination navigation method as claimed inclaim 1, characterized by further comprising a step by which the driveris given an alarm or a driving guidance relating to the short-distancelane change section every time the driver comes near to theshort-distance lane change section every time the driver comes near tothe short-distance lane change section in the case when the set routingline to destination includes the short-distance lane change section. 7.The destination navigation method as claimed in claim 1, displaying atleast one route including a short-distance lane change section and atleast one route including no short-distance lane change section in sucha manner that they can be discriminated from each other, and a step ofmaking the driver select one route out of the plurality of routesdisplayed in the said displaying step.